By Team Aakash Byju's | 29th December 2022
A
Heat is absorbed by a body, but its temperature does not rise. Which of the following statements explains the phenomena?
No increase in internal energy takes place.
B
Only the kinetic energy of vibration increases.
C
D
Only the potential energy of the intermolecular force field increases.
An increase in kinetic energy is balanced by a decrease in potential energy.
The correct answer is
option C. Only the potential energy of the intermolecular force field increases.
Since there is an absorbance of heat energy, there must be a change in internal energy.
Thus, option A is invalid.
We know that kinetic energy(KE) is directly proportional to temperature.
Thus, when there is no change in temperature, there is no change in kinetic energy also.
Thus, option B is invalid.
Increasing KE (temperature)
Increasing IMF
Solid
Liquid
Gas
Since option B is invalid, it concludes that option D is also invalid.
Since there is no change in KE, there is no chance of balancing it with a decrease in potential energy(PE).
It is said that the temperature is not raised, but still, the heat is being absorbed by the body.
This means the intermolecular distance would have increased.
So, the potential energy of the intermolecular force would have changed due to the absorbance of heat.
Thus, only option C is valid.
InterMolecular Distance (r)
r
e
σ
Attractive
Repulsive
Potential Energy
ε